Antenna



FIG. 1 is a front elevation view of an antenna;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a front perspective view thereof; and,

FIG. 4 is a perspective view thereof in a bent configuration.

The broken line portion of the figures is included to show unclaimed subject matter only and forms no part of the claimed design. 

CLAIM The ornamental design for an antenna, as shown and described. 